What Is the Final Temperature of a Mixture of Oxygen and Air?

AI Thread Summary
The discussion centers on calculating the final temperature of a mixture of oxygen at 105 K and room air at 307 K, mixed at equal mass flow rates. The initial calculation provided was 210 K, but there is uncertainty about its validity. The user emphasizes the need to clearly define delta T, which represents the temperature change for both substances. To find the final temperature, the equations for heat transfer must be equated, considering the specific heat capacities of oxygen and air. The conversation highlights the importance of understanding thermodynamic principles to solve the problem accurately.
gamx
Messages
6
Reaction score
0

Homework Statement



An oxygen supply system mixes oxygen at 105 K and room air at 307 K at equal mass flow rates. What is the temperature of the resulting mixture in K? (c of oxygen = 918 J/kgK, c of air = 1012 J/kgK)

Homework Equations



Q=mc\Delta T and Q=mL_f

The Attempt at a Solution



(105 x 918 + 1012 x 307) / (918 + 1012) = 210 K ( not a single inkling about the validity of the answer ) -_- . The inadequancy of my lecture notes really leaves me clueless =/
 
Last edited:
Physics news on Phys.org
firstly, we must define delta T clearly. delta T is the change in temperature of both mixtures, and we can define delta T as the temepreature change from 105K, and then the temperature change for the room air is (307-105)=202K, 202-deltaTK.

Equate both equations together in the first equation you gave and you have the answer.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

I try to solve a thermodynamics problem on heat transfer
Replies
3
Views
2K
Change in temperature of air in a closed system
Replies
16
Views
2K
Calculate the Mass of Ice cubes needed to cool a soft drink
Replies
10
Views
3K
Thermal physics problem -- Pressure and temperature of air in a refrigerator
Replies
2
Views
4K
Thermodynamics relating to temperature and phase changes
Replies
1
Views
1K
Mass of Ice required to achieve a certain final Temperature
Replies
3
Views
2K
Thermodynamics relating to temperature and phase changes V.2
Replies
1
Views
1K
Thermal Equilibrium of Hot Iron & Water
Replies
5
Views
2K
Solve Thermal Rad. Homework: Box Painted Black, 500 W Light
Replies
11
Views
2K
Finding the Value of M in a Physics Homework Problem
Replies
12
Views
2K

Hot Threads

Recent Insights

Back
Top